The present invention relates to the field of agricultural machinery, more particularly to rolling agricultural stock designed to transport feedstuffs or other materials, and capable of weighing the quantity being transported.
The invention relates more specifically to an agricultural vehicle equipped with a container and a weighing means, especially a dump trailer, a mixing trailer or analogous equipment.
In certain applications in the agricultural sector, it is highly desirable to be able to weigh a load being transported by a vehicle such as a trailer without the need for additional external weighing means, i.e. by incorporating an integrated weighing means that preferably is adjusted for the tare weight of the empty container.
This is the case in particular for mixers or mixing trailers designed to achieve distribution of fibrous, granular and/or powdered feed mixtures in bulk in the form of rations optimized in the nutritional and technico-economic respects.
In this context, weighing is the key element for producing the ration corresponding to the total of the constitutive feedstuffs of a diet distributed daily to satisfy their needs. Thus, in the case of milk production from dairy cattle, the ration must be practically identical at all times; it is composed of rough forage (hay, grass silage and corn silage), succulent feed (cereals) and concentrated feed (legumes, protein grains) to compensate for possible nutritional imbalances.
To obtain a relatively homogeneous mixture to be distributed, these pieces of equipment comprise rotating elements such as screws. This is the case in particular for mixers of the type known by the names “EUROMIX” or “PROFILE” (registered trademarks) of the KUHN Co.
Of course, these mixers also have a drawbar hitch and a rolling device of single-axle or double-axle type (for high-capacity mixers).
In certain alternative embodiments of these known mixers, as well as in the mixer known from the document DE 10348206, the container designed to hold the ration rests on a double axle by way of analog load cells or weighing sensors, preferably directly, i.e. without use of an intermediate chassis. In fact, a construction without chassis is simpler and less expensive, since a complex chassis does not have to be assembled (the chassis is complex because the combination of the body and unloading/mulching equipment has to be suspended).
In this embodiment known from the aforesaid DE document, the container rests on a double axle via two load cells, i.e. via one load cell arranged close to each front wheel (that which is pushed by the load-cell connection). These two load cells normally support most of the load. These two load cells are cantilever-mounted, thus necessitating reinforcement at container height to ensure sufficient structural stability. This limited number of bracing and connecting points does not favor optimum distribution of forces and stresses at the level of the container (generally a box of mechanically welded sheet metal). The weighing means also has at least one additional load cell at the level of the drawbar, more precisely at the level of the hitch eye.
In addition, in high-capacity machines, the load cells, especially the two load cells assuring the container-axle connection, must be dimensioned such that they can support heavy loads. This results in the use of load cells, the vertical space requirement of which is extensive, in particular because of a larger cross section, and the price of which is high. The bottom of the container is therefore displaced (upward) at some distance from the wheels, thus reducing the stability of the mixers in the loaded state (upward displacement of the center of gravity), making their loading more cumbersome and possibly preventing them from moving through doors or access passageways of limited height.